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> A relevant headline is "40% of A-level results were downgraded from teachers' predictions." - however, that seems normal and expected to me; do we have the eq

> A relevant headline is "40% of A-level results were downgraded from teachers' predictions." - however, that seems normal and expected to me; do we have the equivalent numbers from last year, comparing the teacher's prodictions with the actual exam results? It's about 39%. The problem is that in a normal year, everyone comes out an exam with a rough sense of how they've done. If you come out feeling like you bombed it then seeing your B become a C is not going to be a surprise. The issue is that "predicted grades" are not expectation values in a statistical sense, if they were then teachers would be pretty consistently doing a bad job of forecasting them. A predicted grade is based on an assessment of ability: "What do I think little Johnny is capable of when he takes his exam in however months time". Now in theory, results can be both better and worse than that prediction. In practice, the fact that the scale is closed ended (and many more are near the top than the bottom) means that it is more common for the variability of exam performance to lead to slightly worse performance. In other words, more pupils underperform their ability based prediction on exam day than outperform it. So there is nothing inherently wrong with reducing grades from the centre assessed grades, many newspaper headlines are treating this like the CAG is the "real" grade that is somehow being taken away. If you look at this table: https://twitter.com/Samfr/status/1293979033458417668/photo/1 https://twitter.com/Samfr/status/1293979033458417668/photo/1 you can see that the overall grade distribution produced by the model for this year is similar to that for previous years. Not surprising since that is by design. The problem here is that Ofqual is treating grade inflation like it's the worth possible thing that could happen and has essentially sacrificed individual fairness on the altar of aggregate consistency.

r_c_a_d 6y ago
Even if you know it is likely that 2 out 5 students who you assess as grade B will have a bad day and get a C in the exam, you don't know which 2 of the 5, so you have to assess them all as a B. Ranking students might be roughly correct, but many of the rankings in the middle where students are very similar are basically random.
- NLips 6y ago
  Even ranking students isn't a good answer on the individual level. Imagine there are two schools: A typical small private school, which normally achieves high grades, and a larger state school which normally achieves a broader spread. Normally the highest individual grade is achieved at the private school. The historic average of the private school might be A-star, A, B, but predictions were A-star, A, A. Rankings are correct to the individuals' abilities. "Actual" or "deserved" standard could be A, A, A or A, A, B. The state school's top 3 grades are normally A, A, B. This year you have a student who's capable (and likely) to achieve an A*. Teacher predictions for the top three grades are therefore A-star, A, A. Rankings are still correct according to ability. Across the country the top 6 grades are normally A-star, A, A, A, B, B. The private school uses the teacher predictions, because it has a small class: A-star, A, A. We're now left with only A, B, B available to give to the top students at the state school, so the A-star, A, A assessed students are awarded A, B, B. Every one is a downgrade. But it's OK, because across the country there's no grade inflation.
  - r_c_a_d 6y ago
    That is exactly what happened to my son's Computer Science class. They all got shifted down. Thankfully the UK government have now decided to revert to the teacher assessed grades.

r_c_a_d 6y ago

Even if you know it is likely that 2 out 5 students who you assess as grade B will have a bad day and get a C in the exam, you don't know which 2 of the 5, so you have to assess them all as a B. Ranking students might be roughly correct, but many of the rankings in the middle where students are very similar are basically random.

NLips 6y ago
Even ranking students isn't a good answer on the individual level. Imagine there are two schools: A typical small private school, which normally achieves high grades, and a larger state school which normally achieves a broader spread. Normally the highest individual grade is achieved at the private school. The historic average of the private school might be A-star, A, B, but predictions were A-star, A, A. Rankings are correct to the individuals' abilities. "Actual" or "deserved" standard could be A, A, A or A, A, B. The state school's top 3 grades are normally A, A, B. This year you have a student who's capable (and likely) to achieve an A*. Teacher predictions for the top three grades are therefore A-star, A, A. Rankings are still correct according to ability. Across the country the top 6 grades are normally A-star, A, A, A, B, B. The private school uses the teacher predictions, because it has a small class: A-star, A, A. We're now left with only A, B, B available to give to the top students at the state school, so the A-star, A, A assessed students are awarded A, B, B. Every one is a downgrade. But it's OK, because across the country there's no grade inflation.
- r_c_a_d 6y ago
  That is exactly what happened to my son's Computer Science class. They all got shifted down. Thankfully the UK government have now decided to revert to the teacher assessed grades.